POPULATION-DYNAMICS OF LEMNISCOMYS ROSALIA (MURIDAE, RODENTIA) IN A SWAZILAND GRASSLAND - EFFECTS OF FOOD AND FIRE

The effects of food supplementation on a population of Lemniscomys ros alia were studied experimentally in a grassland habitat in Swaziland. Food was added bi-weekly to two 1-ha grids, while a single 1-ha grid s erved as the control. Rodent traps were set monthly over a 12 month pe riod. Food supplementation may have affected the density of L. rosalia , but did not affect any other features of the population. Breeding co mmenced in September and ended in April (males) and May (females). Rec ruitment of juveniles occurred between January and March. Adult mean b ody mass increased from-a low in winter (June/July) to a high in late summer (February). The drop in mean body mass in autumn was due to the disappearance of heavy adults and entry of the lighter subadults into the population. Mean survival of L. rosalia was low; 81% of all captu red individuals disappeared within four months. An unscheduled fire bu rnt part of the study area and hence allowed an assessment of the effe ct of fire on L. rosalia. The fire did not cause undue mortality of L. rosalia, however, burnt areas were avoided for three months until gra ss cover had sufficiently increased.